[Dsg-mvt] Request new manometer for Eel premix gas system + interlock

[Brian Eng]

Hi Franck,

The pressure should be around 300 psi on a new bottle (depending on the temperature).

Changing that gauge with a different one would require DA approval. I've CC'd Matt so he can chime in. We (DSG / as pressure system technicians) can only change a component for the exact part number when requested to by the system owner (Bob Miller).

George already looked and he doesn't have an appropriate gauge. If this is a time critical item we can order it via webstock (it should be here in a day or two) once we have a part number from Matt.

Thanks
--
Brian Eng
Detector Support Group
757-269-6018

> On Jun 8, 2017, at 4:43 PM, Franck Sabatie <sabatie at jlab.org> wrote:
> 
> Hello,
> 
> as was pointed out several times before, the current Eel premix gas cylinder uses a manometer that goes up to 4000 psi full scale.
> 
> A full premix cylinder reads 0 on that scale: this is useless to check if the bottle is empty or not.
> 
> It is URGENT to change this manometer so that we know when to change the cylinder. I'm not sure what is the pressure expected on those bottles, George probably knows.
> 
> Then a procedure has to be put in place to change the cylinder: someone (to be defined) has to check every day the manometer and act accordingly. This has to be discussed within the DSG.
> 
> Note that there is currently no interlock between the gas system and the HV. If no gas flows through the system, it may eventually trip the HV. It should not damage the system but it's still problematic. Such an interlock will be developed this summer (maybe Wesley and Nathan can figure out how to do that through EPICS). In the meantime, Wesley will put in place an EPICS alert through an automated email sent to some email addresses (dsg-mvt included) when no gas pressure / flow is detected at the entrance of the gas system. Several people will know how to turn off the HV of the MVT system when they receive this email and they should !
> 
> Thank you,
> Franck